feat: Current window position

[Squidonomics]

Implements the following functions:
/session/:sessionId/window/:windowHandle/maximize
/session/:sessionId/window/:windowHandle/position

[tristanlabelle]

Thanks for your contribution! We can design this API to have a closer shape to the Element API. I left some comments.

[tristanlabelle]

Thanks for the update, the new Window struct is looking good, we just need an accessor from Session so that we don't need to duplicate members there.

[Squidonomics]

My most recent commit should address all the comments. Sorry for the delay I've been running through the interview circuit so not a lot of free time.

[tristanlabelle]

Thanks for iterating! The docs now need to be updated but the code looks good!

[tristanlabelle]

Attempted a merge in the GitHub actions editor, hopefully I didn't mess it up.

[tristanlabelle]

Oops I messed up the merge by adding public var windowHandle: String to SessionOrientation.Get. I'm not sure I can change it. @Squidonomics, could you remove it?

[Squidonomics]

Just pushed up a fix for that @tristanlabelle this is ready to go.